CN108390093A - A kind of lithium battery of the positive electrode based on surface chemical modification - Google Patents
A kind of lithium battery of the positive electrode based on surface chemical modification Download PDFInfo
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract
The present invention relates to lithium ion batteries（Abbreviation lithium battery）And its positive electrode of surface chemical modification, belong to technical field of lithium batteries.A kind of lithium battery of the positive electrode based on surface chemical modification, which is characterized in that used the positive electrode powder of surface chemical modification.It is cathode by positive active material, lithium piece of the anode material of lithium battery of surface chemical modification, using organic electrolyte, is assembled under the anhydrous and oxygen-free environment full of argon gas, and obtains the button-type lithium cell that chemical property significantly improves.The present invention is conducive to corrosion of the HF for inhibiting to generate by electrolyte decomposition to lithium battery positive pole active substance, improves the chemical property of lithium battery.
Description
Technical field
The present invention relates to lithium ion batteries（Abbreviation lithium battery）And its positive electrode of surface chemical modification, belong to lithium battery
Technical field.
Background technology
Lithium battery is widely used in the multiple fields such as mobile phone and laptop.Corruption due to electrolyte to electrode material
The reasons such as erosion, lithium battery self discharge, lithium battery its capacity meeting slow-decay after charging, reduce its chemical property.
In order to improve the performance of lithium battery, people have carried out a variety of effort.Such as CN102299273A, CN102299292A
Attempt to realize the ageing-resistant of lithium battery by improving the sealed connection of lithium battery top cap electrode column；CN204464324U、
CN104681752A attempts to realize the ageing-resistant of lithium battery by improving the form of lithium battery.
CN103682436A discloses a kind of high anti-aging electrolyte for lithium ion battery containing manganese and application thereof, the electrolyte
It is made of four constituents：Lithium salts, non-aqueous organic solvent, stabilization additives and other functional additives, wherein lithium salts are with such as
One or more kinds of compositions in the compound of lower molecular formula：LiPF6、LiBF4、LiBOB、LiClO4、LiPF3(C2F5)3,
Stabilization additives are selected from the one or more in three (trimethyl silane) phosphates, methane-disulfonic acid methylene ester, ethanol amine
Combination, the addition of stabilization additives is the 0.1~5% of electrolyte total weight.
CN107474450A discloses a kind of novel high-barrier corrosion-resisting lithium battery composite soft packaging film, formula include with
The each component of lower parts by weight：Nano-calcium carbonate Ca45~60 part, 20~35 parts of carbon nanotube, 25~30 parts of oleamide, horse
Come 20~30 parts of acid anhydrides, 10~18 parts of graphene, 6~10 parts of vinyl organosilicon resin, 5~8 parts of sepiolite, polytetrafluoro
25~30 parts of ethylene, 20~30 parts of benzotriazole, 12~16 parts of polyvinyl butyral, 8~12 parts of Lauryl Alcohol ester,
8~10 parts of linear phenol-aldehyde resin and several auxiliary agents；The novel high-barrier corrosion-resisting lithium battery composite soft packaging film of the present invention,
Material is light flexible, plays high intensity, high abrasion, high temperature resistant, corrosion-resistant, anti-aging, warpage preventing effect, to improve lithium electricity
The sealing performance in pond, and effectively extend the service life of lithium battery, and expand the use scope of lithium battery.
CN107189402A discloses the modified engineered plastic material for manufacturing lithium cell core shell, also discloses use
In the preparation method of the modified engineered plastic material of manufacture lithium cell core shell.Modified engineered plastic material provided by the invention
It can be used to manufacture lithium cell core shell, instead of the lithium cell core shell of metal aluminum alloy material, while have well
Vapor water barriers performance, heat conduction, flame retardant property, the chemical erosion of electrolyte resistance etc. have excellent heat aging performance, can meet
The long-time service of battery core under various conditions.
Positive electrode（Also known as cathode material）It is the important component of lithium battery, it decides that the energy of lithium battery is close
Degree, cyclical stability, safety and cost（Electrochimica Acta, 2016, 222, 685-692）.Common lithium
Cell positive material has：Cobalt acid lithium (LiCoO2, be abbreviated as LCO), LiMn2O4 (LiMn2O4, be abbreviated as LMO), LiFePO4
(LiFePO4, it is abbreviated as LFP) and manganese, nickel doping cobalt acid lithium ternary electrode material (LiNi x Mn y Co z O2, x + y + z = 1)。
Above-mentioned positive electrode there is a problem that in actual application two kinds it is important：First, positive electrode electronic conductivity and ion
The low problem of conductivity；Second is that positive electrode is exposed to the problem of performance degradation in surrounding air, i.e. problem of aging.
Just there are researcher discovery, positive electrode early in 2008（Such as LFP, carbon coating LFP (LFP/C)）It is exposed to
It contacts in air or with water, since the hydrophily of Li can cause positive electrode to take off lithium, decays so as to cause its chemical property
（Electrochemical and Solid-State Letters, 2008, 11, A4-A8; Journal of Power
Sources, 2008, 185, 698-710; Electrochemical and Solid-State Letters, 2008,
11, A12-A16.）.Positive electrode in weighing, dispense, take and can be contacted with surrounding air during electrode fabrication, with air
Positive electrode after contact undergoes long-time storage（January or several months）Afterwards, chemical property can be substantially reduced.
CN102544514A discloses a kind of surface-carbon-modified cathode anode material for lithium-ion batteries and preparation method thereof, is first
Anode material for lithium-ion batteries LiMn is made0.5Ni1.5O4, then with LiMn obtained0.5Ni1.5O4With organic solution 80~100
°C heating condition under the concurrent biochemical reaction of uniform stirring 15~60 minutes, obtain to surface and be coated with high molecular lithium-ion electric
Pond positive electrode, by being filtered, washed and drying, then in an inert atmosphere in 550 ~ 750 °C of carbonizations, to obtain surface
The anode material for lithium-ion batteries of carbon modification.
CN104600282A discloses a kind of surface modifying and decorating anode material for lithium-ion batteries（Such as cobalt acid lithium, lithium nickelate
Deng）And preparation method thereof,（1）Anode material for lithium-ion batteries and one or more kinds of metal acetate salt are sufficiently mixed；
（2）Said mixture is increased into temperature to 80 ~ 450 °C, the acetate of low melting point in mixture is made to reach melting or congruent melting shape
State, and realize complete wetting and completely cladding on positive electrode surface；（3）Temperature is further increased to 300 ~ 800 °C, is made just
The metal acetate salt clad of pole material surface is decomposed into metal oxide clad and metal ion to material internal divergent contour
At doping vario-property layer, surface modified anode material for lithium-ion batteries is obtained.
Positive electrode and carbon or inorganic matter is compound, be conducive to the electronics and/or ionic conductivity that improve positive electrode.Together
When, such carbon or inorganic matter clad can prevent the hydrone in air and active material to a certain extent（I.e. above
The LiMn0.5Ni1.5O4, cobalt acid lithium, lithium nickelate etc.）It is in direct contact, this is conducive to improve positive electrode in surrounding air
Ageing resistance.But positive electrode surface modification or cladding as described in CN102544514A and CN104600282A is done
Method, since during surface modification or cladding, positive electrode experienced high-temperature burning process, this can cause finishing coat to receive
It contracts, divide, being unevenly distributed, coating incomplete phenomenon.In other words, disposable surface modification or packet are carried out to positive electrode
It covers, is evenly distributed on positive electrode surface it is difficult to obtain, coats complete decorative layer（Journal of Materials
Chemistry, 2011, 21, 14680;Journal of The Electrochemical Society, 2015, 162,
A2201-A2207;Journal of Alloys and Compounds, 2017, 706, 24-40.）, this can undoubtedly be caused
The phenomenon that positive electrode partial denudation.Hydrone in surrounding air can be contacted by diffusion with exposed position, cause positive material
Material takes off lithium, aging, reduces its chemical property.
Secondary surface modification is carried out to carbon coating positive electrode, existing literature there are a large amount of records, such as uses mechanical mixing
（Such as ball-milling method）, mixing method, the in-situ modification method completed in the solution in solvent（Advanced Materials, 2007,
19, 848-851; J. Mater. Chem. A, 2014, 2, 19315-19323; Journal of Power
Sources, 2010, 195, 5351-5359; Angewandte Chemie, 2011, 50, 6884-6887.）.Machinery
Mixing method is unfavorable for realizing active material particle cladding, and the modification method process route based on solvent/solution is long, can generate waste liquid,
It easily leads to active material in modification and takes off lithium.In short, the above method cannot meet carries out secondary surface to positive electrode
The requirement of modification/cladding.
Invention content
In view of the deficiencies of the prior art, the present invention provides a kind of lithium batteries of the positive electrode based on surface chemical modification.
In order to which the problem of performance degradation after contacting with the air, it is right to improve its during transport, storage and use for lithium battery
Tolerance in surrounding air, the present invention improve lithium battery performance by the way that positive electrode is surface modified/is coated to reach
Purpose.Aging after being contacted with surrounding air in view of the positive electrode that lithium battery uses is attributed to not by the exposed of surface modification
Position contacted with the hydrone in surrounding air after caused by take off lithium, it is clear that positive electrode carry out it is secondary cladding be improve its
To the effective way of surrounding air ageing resistance.Secondary surface modification/cladding is carried out to positive electrode, to be met as far as possible such as
Lower requirement：（1）It is complete to the cladding of positive electrode particle, to cut off contact path of the hydrone with active material；（2）Cladding
Layer component is as conductive as possible, cannot reduce the high rate performance of material；（3）The thickness of clad wants moderate, and cladding layer component exists
Shared mass percent cannot be excessive in compound, i.e., cannot be to sacrifice the specific energy of positive electrode as cost；（4）Technique
Simple, no waste is environmental-friendly.The present invention uses aumospheric pressure cvd technology, makes coating material molecular vapor
It is deposited on positive electrode particle surface, and in particle surface growth in situ, forms isolated environment air water molecule and positive electrode
The polymer film in active contacts channel.The positive electrode modified using the technology of the present invention has surrounding air good
Tolerance, and it can be obviously improved the chemical property of positive electrode, this is conducive to improve the lithium based on surface modification positive electrode
The chemical property of battery.
Term is explained：
LCO：Cobalt acid lithium (LiCoO2)。
LCO/C：Carbon coating cobalt acid lithium (LiCoO2/C)。
LMO:LiMn2O4 (LiMn2O4)。
LMO/C:Carbon coating LiMn2O4 (LiMn2O4/C)。
LFP：LiFePO4 (LiFePO4)。
LFP/C：Carbon-coated LiFePO 4 for lithium ion batteries (LiFePO4/C)。
LNMCO:Manganese, nickel doping cobalt acid lithium ternary electrode material (LiNi x Mn y Co z O2, x + y + z = 1)。
LNMCO/C：Carbon coating manganese, nickel adulterate cobalt acid lithium ternary electrode material.
Carbon coating cobalt acid lithium (LiCoO2/ C), carbon coating LiMn2O4 (LiMn2O4/ C), carbon-coated LiFePO 4 for lithium ion batteries (LiFePO4/
C), carbon coating manganese, nickel doping cobalt acid lithium ternary electrode material are referred to as carbon coating positive electrode.
" carbon " described in above-mentioned " carbon coating " is synthesis carbon, i.e., with organic compound, organic polymer, organic polymer
For precursor, the part graphitized carbon obtained by high-temperature heat treatment.
Aging：Positive electrode is exposed to certain time in surrounding air, compared with the starting positive electrode, electrochemistry
The phenomenon that performance degradation.
Ageing resistance：The positive electrode of surface chemical modification is exposed to certain time in surrounding air, and without table
The starting positive electrode of face modification is compared, the unattenuated phenomenon of chemical property；Alternatively, with it is in identical environment,
The phenomenon that positive electrode of non-surface modification is compared, and chemical property attenuation degree is substantially reduced.
Curing：After coating material is mixed with positive electrode powder to be finished in closed container, coating material
Molecule evaporation is deposited on positive electrode powder surface, then nucleation in situ, growth, the process for forming polymer.
Specific discharge capacity：The electricity that unit mass active material or battery can release, unit：MAh/g（mA h
g-1）.
Capacity retention ratio：The electricity that active material is released under certain current density and the electric discharge under a certain current density
The ratio between amount, alternatively, active material recycles the electricity and discharge capacity for the first time that can be released after a fixing turn under certain current density
The ratio between.
Detailed description of the invention
A kind of lithium battery of the positive electrode based on surface chemical modification, which is characterized in that using surface chemical modification just
Pole material powder.Preferably, the lithium battery is button-type lithium cell.
The button-type lithium cell recycles the specific discharge capacity of 100 circles at 1 C（Based on positive electrode）Reach 70 ~
140 mA h g‒1, capacity retention ratio is 85 ~ 92%, and capacity is 0.4 ~ 1.8 mW h.
The button-type lithium cell, it is positive active material, lithium piece to have used the positive electrode powder of surface chemical modification
For cathode, microporous polypropylene membrane is diaphragm.
Preferably, the button cell further includes electrolyte, and electrolyte is 1 mol L‒1LiPF6、LiBF4、 LiN
(SO2CF3)2Or LiN (SO2C2 F5) it is dissolved in ethylene carbonate：Dimethyl carbonate：Diethyl carbonate（Volume ratio is 1:1:1）It is mixed
Close liquid.
A kind of preparation method of button-type lithium cell, which is characterized in that used surface chemical modification of the present invention
Positive electrode powder be positive active material, lithium piece is cathode, 1 mol L‒1LiPF6、LiBF4、 LiN(SO2CF3)2Or
LiN(SO2C2 F5) it is dissolved in ethylene carbonate：Dimethyl carbonate：Diethyl carbonate（Volume ratio is 1:1:1）For electrolyte, micropore
Polypropylene screen is diaphragm, and CR2032 button cells are assembled in the glove box full of dry argon gas.Its assembling sequence is anode
Shell-positive plate-electrolyte-diaphragm paper-electrolyte-lithium piece-negative electrode casing.Sealing pressure is 45-55 kg/cm3。
The positive electrode powder of the surface chemical modification is that the surface of positive electrode has polymer-modified layer.Institute
The positive electrode stated is LiCoO2、LiCoO2/C、LiMn2O4、LiMn2O4/C、LiFePO4、LiFePO4/C、LiNi x Mn y Co z O2
(x + y + z=1) or LiNi x Mn y Co z O2/C (x + y + z=1), wherein the quality of carbon in carbon coating positive electrode
Percentage composition is less than 5%.
The polymer-modified layer is conducting polymer oligomer.The conducting polymer oligomer, to contain 8 ~ 14
The oligomer of a monomer, weight average molecular weight distribution are 522 ~ 1276；Molecular weight distribution index is 1.1 ~ 1.3.Preferably, institute
It is aniline, thiophene, pyrroles, 2-aminotoluene, 3- methylanilines, 2- ethyl aniline, 3- ethyl aniline, 2- vinyl benzenes to state monomer
Amine, 3- vinyl aniline, 3,4- ethene dioxythiophenes, 3 methyl thiophene, 3- ethylthiophenes, 3- vinyl thiophenes, 3,4- ethylene
Dioxypyrrole, 1- benzyl -3,4- ethylene dioxies pyrroles, 3- methylpyrroles, 3- N-ethyl pyrrole Ns or 3- vinyl pyrroles.
Preferably, the conducting polymer oligomer, monomer are pyrroles, N 1s high-resolution XPS spectrum figures show positioned at 400,
400.7, the peak of 402 eV.
Preferably, the conducting polymer oligomer, monomer are thiophene, and S 2p figures are shown positioned at 163.8 and 164.8
The peak of eV.
Preferably, the conducting polymer oligomer, monomer are aniline, and N 1s high-resolution XPS spectrum figures, which are shown, to be located at
399.2, the peak of 400.0,401.0 eV.
Preferably, the quality of polymer-modified layer accounts for about the 0.05 ~ 3% of surface modification positive electrode quality.
The positive electrode powder of the surface chemical modification is prepared using following method：
A. under room temperature environment air conditions, positive electrode powder is transferred in container；The volume of powder is held no more than container
Long-pending 60%；
B. it by coating material, is added in the container described in step a, container is sealed；Coating material and positive electrode powder
The volume mass ratio of body is 0.5 30 mL/kg；
C. by mixing in coating material and container of the positive electrode powder described in step b, curing obtains surface chemical modification
, the target positive electrode powder that ageing resistance is strong.
Room temperature environment air conditions described in step a, range of temperature therein are 0 40 °C, surrounding air
Relative humidity is 20 80%.
Positive electrode described in step a is LiCoO2、LiCoO2/C、LiMn2O4、LiMn2O4/C、LiFePO4、
LiFePO4/C、LiNi x Mn y Co z O2 (x + y + z=1) or LiNi x Mn y Co z O2/C (x + y + z=1), wherein carbon
The mass percentage of carbon is less than 5% in clad anode material.
Positive electrode powder described in step a, the mesh of size >=800.Preferably, the positive electrode described in step a
Powder, particle size are 0.1 ~ 18 μm.
Container described in step a is salable, with stirring, the container with charge door.
Container described in step a, material are stainless steel, enamel, enamel, ceramics, glass or plastics.
Coating material described in step b is aniline, thiophene, pyrroles, 2-aminotoluene, 3- methylanilines, 2- ethyls
Aniline, 3- ethyl aniline, 2- vinyl aniline, 3- vinyl aniline, 3,4- ethene dioxythiophenes, 3 methyl thiophene, 3- ethyls
Thiophene, 3- vinyl thiophenes, 3,4- ethylene dioxies pyrroles, 1- benzyl -3,4- ethylene dioxies pyrroles, 3- methylpyrroles, 3- ethyls
Pyrroles or 3- vinyl pyrroles.
Mixing described in step c, mode are stirring, shake or vibrate.
Curing described in step c, curing time are 7 30 days, stir material during curing daily 24 times, stir every time
It is 1 30 min to mix the time.
The present invention is more complicated, and Summary is only described in detail the inventive point relevant portion of the present invention, the present invention
The prior art can be used in non-detailed portion.
Advantageous effect
Currently invention addresses the chemical properties for improving lithium battery（Specific capacity, high rate performance and cyclical stability）.To come to the surface
The anode material of lithium battery for learning modification is positive active material, lithium piece is cathode, using organic electrolyte, in the nothing full of argon gas
It is assembled under water oxygen-free environment, and obtains the button-type lithium cell that chemical property significantly improves.
The acquisition of the anode material of lithium battery of surface chemical modification is to utilize aumospheric pressure cvd technology, makes surface
Electrolyte can be isolated in positive electrode particle surface, growth in situ, formation for dressing agent molecular vapor deposition and active matter is upright
The conducting polymer oligomer of contact, this is conducive to the HF for inhibiting to generate by electrolyte decomposition to lithium battery anode active matter
The corrosion of matter improves the chemical property of lithium battery.
Description of the drawings
Fig. 1 is the XRD diagram of sample：(a) LFP/C; (b) cLFP-2; (c) cLFPM-2; (d) cLFP-4; (e)
cLFPM-4。
Fig. 2 is the graph of molecular weight distribution of the surfaces sample cLFPM-2 pyrroles's oligomer.
Fig. 3 is the N 1s spectrograms of sample：(a) LFP/C; (b) cLFP-2; (c) cLFPM-2.
The SEM that Fig. 4 is sample LFP/C schemes.
The SEM that Fig. 5 is sample cLFPM-4 schemes.
Fig. 6 is using cLFPM-2, LFP/C and cLFP-2 as the high rate performance figure of the lithium battery of positive electrode.
Fig. 7 is the cycle for recycling 100 circles at 1 C using cLFPM-2, LFP/C and cLFP-2 as the lithium battery of positive electrode
Stability curve.
Fig. 8 is using cLFPM-4, LFP/C and cLFP-4 as the high rate performance figure of the lithium battery of positive electrode.
Fig. 9 is the cycle for recycling 100 circles at 1 C using cLFPM-4, LFP/C and cLFP-4 as the lithium battery of positive electrode
Stability curve.
Figure 10 is the XRD diagram of sample：(a) LMO; (b) LMO-2; (c) LMOM-2.
The SEM that Figure 11 is sample LMO schemes.
The SEM that Figure 12 is sample LMOM-2 schemes.
Figure 13 is the S 2p figures of sample：(a) LMO; (b) LMOM-2.
Figure 14 is the TOF LC-MS figures of the surfaces sample LMOM-2 thiophene oligomer.
Figure 15 is the graph of molecular weight distribution of the surfaces sample LMOM-2 thiophene oligomer.
Figure 16 is using LMOM-2, LMO and LMO-2 as the high rate performance figure of the lithium battery of positive electrode.
Figure 17 is the discharge curve using LMOM-2, LMO and LMO-2 as the lithium battery of positive electrode at 1 C.
Figure 18 is the XRD diagram of sample：(a) LNMCO/C; (b) cLNMCOM-2; (c) cLNMCO-2.
The SEM that Figure 19 is sample LNMCO/C schemes.
The EDS that Figure 20 is sample LNMCO/C schemes.
Figure 21 is the N 1s figures of sample：(a) cLNMCOM-2; (b) LNMCO/C; (c) cLNMCO-2.
Figure 22 is that the GPC of the surfaces sample cLNMCOM-2 Oligoanilines schemes.
Figure 23 is using LNMCOM-2, LNMCO/C and cLNMCO-2 as the high rate performance figure of the lithium battery of positive electrode.
Figure 24 be the lithium battery of positive electrode at 1 C using LNMCOM-2, LNMCO/C and cLNMCO-2 electric discharge it is bent
Line chart.
Table 1 is the unit cell volume and pore volume tables of data of sample.
Table 2 is the electrochemical performance data table of different lithium batteries.
Specific implementation mode
It is further elaborated below by specific embodiment and in conjunction with attached drawing to technical scheme of the present invention, these embodiments
It is intended merely to illustrate technical scheme of the present invention, and the limitation to the claims in the present invention content cannot be considered as.
In embodiment
LFP, LMO, LNMCO, LCO, LFP/C, LMO/C, LNMCO/C, LCO/C, lithium piece, electrolyte win electrochemical material purchased from match
Net；
Pyrroles is purchased from Shanghai Tong Yuan Chemical Co., Ltd.s；
Aniline, polyvinylpyrrolidone（NMP）Purchased from Tianjin great Mao chemical reagents corporations；
Thiophene is purchased from Tianjin Long Yu Chemical Co., Ltd.s；
2- ethyl aniline, 3,4- ethene dioxythiophenes, 3- N-ethyl pyrrole Ns, 3- vinyl thiophenes, 3- ethyl aniline are purchased from Mike woods
Biochemical technology Co., Ltd.
X-ray powder diffraction (XRD) figure of sample is through German Bruker companies Advance D8 in description of the invention
The detection of X-ray powder diffraction instrument obtains；The molecular weight distribution of sample surfaces oligomer is through U.S.'s Waters E2695 gel infiltrations
Chromatograph (GPC) detection obtains；Level four bars flight time liquid phase-mass spectrogram (TOF LC-MS) is through 6520 level four bars of Agilent
Flight time liquid phase-mass spectrometer detection obtains；Scanning electron microscope (SEM) figure, X-ray energy dispersive spectrum (EDS) and element point
Butut is detected through Hitachi S-4800 field emission scanning electron microscopes and is obtained；The transmission electron microscope photo (TEM) of sample is through Japanese JEOL
Company's JEM-2100 transmission electron microscopes detection obtains；X-ray photoelectron spectroscopy (XPS) is through Thermo Fisher
The detection of 250 x-ray photoelectron spectroscopies of Scientific Escalab obtains；The chemical property of sample is through CHI 660E
Electrochemical analyser and the detection of LANHE CT2001A cell testers obtain.
Unless otherwise instructed, the size of positive electrode powder of the present invention is 0.1 ~ 18 μm.In above-mentioned size range
The purpose of the present invention is inside can reach, those skilled in the art can select the size range of powder as needed.
Embodiment 1
(1) preparation of the LFP/C powders of surface modification
5 μ L pyrroles are added in the 50 mL containers for filling 10 g LFP/C powders, container is sealed, shaking container makes LFP/
C powders are uniformly mixed with pyrroles, are cured 7 days at room temperature.During curing, it is shaken every day container 2 times, each shake time is no less than
1 min obtains the LFP/C powder samples of surface modification, which is referred to as cLFPM after the maturation period.
(2) senile experiment
The container stopper for filling cLFPM samples is opened, so that cLFPM samples is exposed in surrounding air, to make sample and surrounding air
It comes into full contact with, daily shakes container occlusion 3 times, each shake time is no less than 1 min, opens plug after shaking every time, makes sample
Again it exposes in surrounding air.Ageing time is continuously 2 months, ranging from 15 38 °C of variation of ambient temperature, and humidity changes model
Enclose is 20 75%.Sample after senile experiment is known as cLFPM-2, wherein 2 be ageing time（Month）.
Compare senile experiment
CLFPM samples described in above-mentioned senile experiment are replaced with starting LFP/C samples, remaining experimental implementation and condition are constant.
Sample after senile experiment is known as cLFP-2, wherein 2 be ageing time（Month）.
(3) assembling of button cell
Using sample is positive active material obtained by embodiment, by sample and acetylene black（Conductive agent）, Kynoar（PVDF glues
Mixture）In mass ratio 7:2:Appropriate NMP is added in 1 mixing, and grinding is abundant, obtains slurry；
Slurry is uniformly coated on aluminium foil（Collector）On, the aluminium foil after coating is placed in vacuum drying chamber, in 80 °C of dryings
12 h；
With twin rollers by the aluminium foil two pairs of rollers after drying（Twin rollers slit is 0.1 mm）, the aluminium foil after two pairs of rollers is cut into slicer
The disk of a diameter of 12 mm, obtains positive plate；
CR2032 type button cells, using lithium piece as cathode, 1 mol L are assembled in the glove box full of argon gas, anhydrous and oxygen-free‒1
LiPF6It is dissolved in ethylene carbonate：Dimethyl carbonate：Diethyl carbonate（Volume ratio is 1:1:1）For electrolyte, capillary polypropylene
Film is diaphragm, and assembling sequence is anode cover-positive plate-electrolyte-diaphragm paper-electrolyte-lithium piece-negative electrode casing, sealing
Pressure is 50 kg/cm3。
Using CHI 660E electrochemical analysers and LANHE CT2001A cell testers, to the button cell assembled
Chemical property evaluated.
Embodiment 2
(1) preparation of the LFP/C powders of surface modification
20 μ L pyrroles are added in the 50 mL containers for filling 10 g LFP/C powders, container is sealed, shaking container makes
LFP/C powders are uniformly mixed with pyrroles, are cured 30 days at room temperature.During curing, it is shaken every day container 2 times, shakes the time every time
No less than 1 min obtains the LFP/C powder samples of surface modification, which is referred to as cLFPM after the maturation period.
(2) senile experiment
The container stopper for filling cLFPM samples is opened, so that cLFPM samples is exposed in surrounding air, to make sample and surrounding air
It comes into full contact with, daily shakes container occlusion 3 times, each shake time is no less than 1 min, opens plug after shaking every time, makes sample
Again it exposes in surrounding air.Ageing time is continuously 4 months, ranging from 15 40 °C of variation of ambient temperature, and humidity changes model
Enclose is 20 80%.Sample after senile experiment is known as cLFPM-4, wherein 4 be ageing time（Month）.
Compare senile experiment
CLFPM samples described in above-mentioned senile experiment are replaced with starting LFP/C samples, remaining experimental implementation and condition are constant.
Sample after senile experiment is known as cLFP-4, wherein 4 be ageing time（Month）.
(3) assembling of button cell
Using sample is positive active material obtained by embodiment, by sample and acetylene black（Conductive agent）, Kynoar（PVDF glues
Mixture）In mass ratio 8:1:Appropriate NMP is added in 1 mixing, and grinding is abundant, obtains slurry；
Slurry is uniformly coated on aluminium foil（Collector）On, the aluminium foil after coating is placed in vacuum drying chamber, in 80 °C of dryings
12 h；
With twin rollers by the aluminium foil two pairs of rollers after drying（Twin rollers slit is 0.08 mm）, the aluminium foil after two pairs of rollers is cut with slicer
At the disk of a diameter of 12 mm, positive plate is obtained；
CR2032 type button cells, using lithium piece as cathode, 1 mol L are assembled in the glove box full of argon gas, anhydrous and oxygen-free‒1
LiPF6It is dissolved in ethylene carbonate：Dimethyl carbonate：Diethyl carbonate（Volume ratio is 1:1:1）For electrolyte, capillary polypropylene
Film is diaphragm, and assembling sequence is anode cover-positive plate-electrolyte-diaphragm paper-electrolyte-lithium piece-negative electrode casing, sealing
Pressure is 50 kg/cm3。
Using CHI 660E electrochemical analysers and LANHE CT2001A cell testers, to the button cell assembled
Chemical property evaluated.
Interpretation of result
Fig. 1 is the XRD diagram of sample cLFPM-2, LFP/C and cLFP-2.It will be seen from figure 1 that each diffraction maximum in Fig. 1 a, b, c
LFP in position and document（JCPDS 83-2092）The position of each diffraction maximum is very identical, this explanation is old by surface modification, air
After change, the object of LFP components is mutually without substantially changeing in cLFPM-2 with cLFP-2 samples.But from the change of sample unit cell volume
Change is seen（Table 1）, compared with LFP/C, the unit cell volume of cLFP-2 slightly reduces, and the unit cell volume of cLFPM-2 is almost unchanged；
The reduction of cLFP-2 unit cell volumes is caused by taking off lithium due to LFP.The result shows the sample of non-surface modification can be by ring
Border air aging, and the sample Jing Guo surface modification will not be by surrounding air aging.
The pyrroles added in experimentation can be in LFP/C after being adsorbed by LFP/C particle surfaces by vapor deposition
The synergistic effect of micro-air is lower in the metal ion and system of surface exposure aoxidizes, polymerize, in exposed particle surface shape
At one layer of pyrroles's oligomer protective film.Pyrroles's oligomer weight average molecular weight (M w) it is 780, molecular weight distribution index is
1.27 the oligomer that corresponding pyrrole ring average number is 12（Fig. 2）.
Fig. 3 is the N 1s high-resolution XPS spectrum figures of sample.From figure 3, it can be seen that with sample LFP/C（Fig. 3 a）And cLFP-2
（Fig. 3 b）It compares, the cLFPM-2 samples modified by pyrroles's oligomer（Fig. 3 c）Middle N 1s peak-to-peak signals are remarkably reinforced.Position in Fig. 3 c
N H, C N are corresponded to respectively in the peak of 400,400.7,402 eV+With C=N+Component, N 1s of these three components in traditional polypyrrole
It is frequently seen in spectrogram（Synthetic Metals, 2004, 145, 15-22; Polymer Degradation and Stability, 2015, 120, 392-401.）.XPS the result shows that, can be at LFP/C using patented technology of the present invention
Grain surface forms pyrroles's oligomer.
Fig. 4 and Fig. 5 is sample LFP/C（Fig. 4）、cLFPM-4（Fig. 5）SEM figure.Compared with originating LFP/C samples, pass through
Variation of the sample in particle size and pattern after surface modification is difficult to differentiate between, this is because formed in LFP/C particle surfaces
Azole polymer is the result of atomic size thickness.
Molecular dynamics simulation result of calculation shows pyrroles's vapour molecule preferentially at LFP/C carbon layer on surface hole position（I.e.
LFP exposed positions combine）, then nucleation in situ, growth, form the atomic layer level thickness for inhibiting surrounding air to be in direct contact with LFP
Azole polymer protective film.The nitrogen adsorption desorption test result of sample shows with pyrroles and LFP/C volume mass ratios（μL/
g）Increase, the pore volume of sample is gradually reduced（Table 1）.This explanation, the calculated results and experimental result are identical.
Table 1
。
Fig. 6 is using cLFPM-2, LFP/C and cLFP-2 as the high rate performance figure of the lithium battery of positive electrode.Although relatively low
Multiplying power（< 0.5 C）Under, the specific discharge capacity of the lithium battery based on cLFPM-2 and LFP/C is closer to, but compared with high magnification
（≥ 0.5 C）Under, the former specific discharge capacity is apparently higher than the latter.And compared to the lithium battery based on LFP/C, in multiplying power height
In the case of 0.2 C, the specific discharge capacity of the lithium battery based on cLFP-2 is substantially reduced.
Fig. 7 is the cyclical stability song that the lithium battery based on cLFPM-2, LFP/C and cLFP-2 recycles 100 circles at 1 C
Line.It can be seen from the figure that the initial discharge specific capacity of the lithium battery based on cLFPM-2, LFP/C and cLFP-2 be respectively 147,
137 and 132 mA h g‒1, after cycle 100 is enclosed, specific discharge capacity is respectively 137,116 and 97 mA h g‒1, capacity retention ratio
Respectively 88.4%, 84.7% and 73.5%（Table 2）.
Fig. 8 is using cLFPM-4, LFP/C and cLFP-4 as the high rate performance figure of the lithium battery of positive electrode.In multiplying power≤2
When C, the specific discharge capacity of the lithium battery based on cLFPM-4 and LFP/C is closer to, but when multiplying power increases to 5 C, the former
Specific discharge capacity is higher than the latter.And compared to the lithium battery based on LFP/C, it is to be based on cLFP-4 within the scope of 0.1 5 C in multiplying power
The specific discharge capacity of lithium battery be substantially reduced.
Fig. 9 is the cyclical stability song that the lithium battery based on cLFPM-4, LFP/C and cLFP-4 recycles 100 circles at 1 C
Line.The initial discharge specific capacity of three is respectively 140,137 and 121 mA h g‒1, after cycle 100 is enclosed, specific discharge capacity difference
Remain 127,116 and 94 mA h g‒1, capacity retention ratio is respectively 90.7%, 84.7% and 77.7%.（Table 2）.
The above results show compared to based on starting LFP/C positive electrodes lithium battery, the cLFPM- based on surface modification
The lithium battery of 2 positive electrodes, the specific discharge capacity of 100 circle of cycle improves 18.1% under 1 C；And based on non-surface modification,
But by the lithium battery of the cLFP-2 of aging 2 months in surrounding air, the specific discharge capacity of 100 circle of cycle reduces under 1 C
16.4%。
Compared to the lithium battery based on starting LFP/C positive electrodes, the lithium of the cLFPM-4 positive electrodes based on surface modification
Battery, the specific discharge capacity of 100 circle of cycle improves 9.5% under 1 C；And based on non-surface modification but pass through surrounding air
The lithium battery of the cLFP-4 of middle aging 4 months, the specific discharge capacity of 100 circle of cycle reduces 20.0% under 1 C.
Table 2
。
Embodiment 3
(1) preparation of the LMO powders of surface modification
100 μ L thiophene are added in the 50 mL containers for filling 10 g LMO powders, container is sealed, shaking container makes LMO
Powder is uniformly mixed with thiophene, is cured 30 days at room temperature.During curing, it is shaken every day container 2 times, each shake time is no less than
1 min obtains the LMO powder samples of surface modification, which is referred to as LMOM after the maturation period.
(2) senile experiment
The container stopper for filling LMOM samples is opened, so that LMOM samples is exposed in surrounding air, to make sample be filled with surrounding air
It taps and touches, daily shake container occlusion 3 times, each shake time is no less than 1 min, opens plug after shaking every time, makes sample weight
It is new to expose in surrounding air.Ageing time is continuously 2 months, ranging from 5 38 °C of variation of ambient temperature, and range of humidity variation is
20‒75%.Sample after senile experiment is known as LMOM-2, wherein 2 be ageing time（Month）.
Compare senile experiment
LMOM samples described in above-mentioned senile experiment are replaced with starting LMO samples, remaining experimental implementation and condition are constant.It will be old
Change the sample after testing and be known as LMO-2, wherein 2 be ageing time（Month）.
(3) assembling of button cell
Using sample is positive active material obtained by embodiment, by sample and acetylene black（Conductive agent）, Kynoar（PVDF glues
Mixture）In mass ratio 80:12:Appropriate NMP is added in 8 mixing, and grinding is abundant, obtains slurry；
Slurry is uniformly coated on aluminium foil（Collector）On, the aluminium foil after coating is placed in vacuum drying chamber, in 80 °C of dryings
12 h；
With twin rollers by the aluminium foil two pairs of rollers after drying（Twin rollers slit is 0.08 mm）, the aluminium foil after two pairs of rollers is cut with slicer
At the disk of a diameter of 12 mm, positive plate is obtained；
CR2032 type button cells, using lithium piece as cathode, 1 mol L are assembled in the glove box full of argon gas, anhydrous and oxygen-free‒1
LiPF6It is dissolved in ethylene carbonate：Dimethyl carbonate：Diethyl carbonate（Volume ratio is 1:1:1）For electrolyte, capillary polypropylene
Film is diaphragm, and assembling sequence is anode cover-positive plate-electrolyte-diaphragm paper-electrolyte-lithium piece-negative electrode casing, sealing
Pressure is 45 kg/cm3。
Using CHI 660E electrochemical analysers and LANHE CT2001A cell testers, to the button cell assembled
Chemical property evaluated.
Interpretation of result
Figure 10 is the XRD diagram of sample LMO, LMOM-2 and LMO-2.LMO in the position of each diffraction maximum and document in Figure 10（JCPDS
88-1026）The position of each diffraction maximum is very identical, illustrates the object for not changing LMO by surface modification, environmental air aging
Phase.But in terms of the unit cell volume of sample, compared to LMO, the unit cell volume of LMO-2 slightly reduces, and the structure cell body of LMOM-2
Product does not change（Table 1）.The result shows the sample of non-surface modification, being placed 2 months in surrounding air partly to take off
Lithium, aging, and the sample of surface modification has good tolerance in surrounding air.
Figure 11 and Figure 12 is that the SEM of sample LMO and LMOM-2 scheme.Compared with LMO（Figure 11）, LMOM-2 samples（Figure 12）
Variation on granule-morphology and size is difficult to differentiate, this is because thiophen polymer is that atomic size thickness is made in LMOM-2 samples
At.
Figure 13 is the S 2p figures of sample LMO and LMOM-2.Compared with sample LMO（Figure 13 a）, the S 2p signal peaks of LMOM-2
It is remarkably reinforced（Figure 13 b）.Wherein, the peak for being located at 163.8 and 164.8 eV corresponds to S 2p respectively3/2With S 2p1/2Component, this and text
It offers（J. Mat er. Chem. A, 2016, 4, 1 9060–19069）The S 2p of middle polythiophene3/2With S 2p1/2Component peaks are very
It is close.This result shows that, there is thiophen polymer on the surfaces LMOM-2.
Through TOF LC-MS（Figure 14）Show with GPC detections（Figure 15）, the thiophen polymer of LMOM-2 sample surfaces is thiophene
It is low to correspond to the thiophene containing 12 thiphene rings in polymer chain for oligomer, weight average molecular weight 977, breadth coefficient 1.06
Aggressiveness.
Figure 16 is using LMO, LMOM-2 and LMO-2 as the high rate performance figure of the lithium battery of positive electrode.Although in 0.1 C
When, the starting specific capacity of three is closer to, but only based on the lithium battery of LMOM-2 0.1 C cycle 10 circle after have it is higher
Cyclical stability.For high rate performance, the high rate performance of three is followed successively by Li ‖ LMOM-2> Li‖LMO > Li‖LMO-
2。
Figure 17 is discharge curve of the lithium battery based on LMO, LMOM-2 and LMO-2 at 1 C.Three is at 1 C
Specific discharge capacity is respectively 85.8,68.0 and 40.1 mA h g‒1, specific discharge capacity and discharge platform reduce successively.Compared to base
In the lithium battery of LMO, the specific discharge capacity based on the lithium battery of LMOM-2 at 1 C improves 26.2%；And based on LMO-2's
Lithium battery, the specific discharge capacity at 1 C reduce 41.0%.
The above results show compared to based on starting LMO lithium battery, the lithium battery of the LMOM-2 based on surface modification,
Specific discharge capacity under its high rate performance and 1 C multiplying powers significantly improves.
Embodiment 4
(1) preparation of the LNMCO/C powders of surface modification
50 μ L aniline are added in the 50 mL containers for filling 10 g LNMCO/C powders, container is sealed, shaking container makes
LNMCO/C powders are uniformly mixed with aniline, are cured 14 days at room temperature.During curing, it is shaken every day container 2 times, when shaking every time
Between no less than 1 min, after the maturation period surface modification LNMCO/C powder samples, which is referred to as cLNMCOM.
(2) senile experiment
The container stopper for filling cLNMCOM samples is opened, so that cLNMCOM samples is exposed in surrounding air, to make sample and environment
Air comes into full contact with, and daily shakes container occlusion 3 times, and each shake time is no less than 1 min, opens plug after shaking every time, makes
Sample exposes in surrounding air again.Ageing time is continuously 2 months, ranging from 0 26 °C of variation of ambient temperature, humidity variation
Ranging from 20 70%.Sample after senile experiment is known as cLNMCOM-2, wherein 2 be ageing time（Month）.
Compare senile experiment
CLNMCOM samples described in above-mentioned senile experiment are replaced with starting LNMCO/C samples, remaining experimental implementation and condition are not
Become.Sample after senile experiment is known as cLNMCO-2, wherein 2 be ageing time（Month）.
(3) assembling of button cell
Using sample is positive active material obtained by embodiment, by sample and acetylene black（Conductive agent）, Kynoar（PVDF glues
Mixture）In mass ratio 7:2:Appropriate NMP is added in 1 mixing, and grinding is abundant, obtains slurry；
Slurry is uniformly coated on aluminium foil（Collector）On, the aluminium foil after coating is placed in vacuum drying chamber, in 80 °C of dryings
12 h；
With twin rollers by the aluminium foil two pairs of rollers after drying（Twin rollers slit is 0.1 mm）, the aluminium foil after two pairs of rollers is cut into slicer
The disk of a diameter of 12 mm, obtains positive plate；
CR2032 type button cells, using lithium piece as cathode, 1 mol L are assembled in the glove box full of argon gas, anhydrous and oxygen-free‒1
LiPF6It is dissolved in ethylene carbonate：Dimethyl carbonate：Diethyl carbonate（Volume ratio is 1:1:1）For electrolyte, capillary polypropylene
Film is diaphragm, and assembling sequence is anode cover-positive plate-electrolyte-diaphragm paper-electrolyte-lithium piece-negative electrode casing, sealing
Pressure is 55 kg/cm3。
Using CHI 660E electrochemical analysers and LANHE CT2001A cell testers, to the button cell assembled
Chemical property evaluated.
Interpretation of result
Figure 18 is the XRD diagram of sample LNMCO/C, cLNMCOM-2 and cLNMCO-2.In Figure 18 a, b, c the position of each diffraction maximum and
LNMCO in document（Chem. Mater. 2005, 17, 3695-3704）The position of each diffraction maximum is very identical, this illustrates process
After surface modification, air aging, the object of LNMCO components is mutually without substantially changeing in cLNMCOM-2 with cLNMCO-2 samples.
The R factors of sample can be calculated according to Figure 18（(I 006 + I 012)/I 101）, the R of LNMCO/C, cLNMCOM-2 and cLNMCO-2 because
Son is respectively 0.43,0.41 and 0.50.From the point of view of the R factors, by the sample of burin-in process again after surface modification, R because
Son is closer to initial sample；And non-surface modification is placed in the sample of aging in surrounding air, R factor variations are larger.
This explanation, places 2 months in surrounding air, can make LNMCO/C agings.
The SEM and EDS that Figure 19 and Figure 20 is LNMCO/C scheme.The class ball that sample LNMCO/C is mainly 9 13 μm by size
Shape particle forms, and the particle of these large-sizes is made of smaller 0.8 0.9 μm of the submicron particles accumulation of size
（Figure 19）.EDS analysis results（Figure 20）Show that the atomic ratio of tri- kinds of elements of Ni, Mn, Co in LNMCO/C samples is 5:3:2, this
Illustrate that the LNMCO/C samples in embodiment are LiNi0.5Mn0.3Co0.2O2/C。
Figure 21 is the N 1s spectrograms of sample cLNMCOM-2, LNMCO/C and cLNMCO-2.With LNMCO/C and cLNMCO-2 phases
Than the N 1s peak-to-peak signals of cLNMCOM-2 samples are remarkably reinforced, this cLNMCOM-2 sample surfaces of explanation Jing Guo surface modification has N
Element.Wherein, positioned at the peak of 399.2,400.0,401.0 eV be attributed to respectively the N of quinone ring=, the NH of phenyl ring and polaron N+
=.It is very close in the N 1s spectrograms of these polyanilines of N components synthesized by conventional solution method（Colloid Polym. Sci.
2017, 295, 1527-1534）, this illustrates the aniline for being adsorbed on the surfaces LNMCO/C, aniline polymerization is formd by oxidation polymerization
Object.
Show through GPC detections（Figure 22）, the aniline polymer of cLNMCOM-2 sample surfaces is Oligoanilines, heavy
Molecular weight is 1126, breadth coefficient 1.1, the Oligoanilines containing 12 aniline units in corresponding polymer chain.
Figure 23 is using cLNMCOM-2, LNMCO/C and cLNMCO-2 as the high rate performance figure of the lithium battery of positive electrode.
Under each multiplying power, the specific discharge capacity of Li ‖ cLNMCO-2 is below Li ‖ LNMCO/C.On the contrary, under the multiplying power more than 0.2 C,
The specific discharge capacity of Li ‖ cLNMCOM-2 is above Li ‖ LNMCO/C.
Although at 0.1 C, the starting specific capacity and the starting specific capacity of Li ‖ LNMCO/C of Li ‖ cLNMCOM-2 more connect
Closely, but after 10 circle of cycle, the former specific capacity is apparently higher than the latter.For Li ‖ cLNMCOM-2, after 10 circles are recycled at 2 C,
Its specific discharge capacity is 88.9 mA h g‒1, compared to the starting specific capacity at 0.1 C, capacity retention ratio 51.5%.And
For Li ‖ LNMCO/C, after 10 circles are recycled at 2 C, specific discharge capacity is 52.8 mA h g‒1, compared to rising at 0.1 C
Beginning specific capacity, capacity retention ratio 30.8%.
Figure 24 is discharge curve of the lithium battery based on cLNMCOM-2, LNMCO/C and cLNMCO-2 at 1 C.From Figure 24
As can be seen that specific discharge capacity of the three at 1 C is respectively 130.7,107.2 and 93.5 mA h g‒1.Compared to Li ‖
Specific discharge capacities of LNMCO/C, Li the ‖ cLNMCOM-2 at 1 C improves 21.9%；And electric discharges of the Li ‖ cLNMCO-2 at 1 C
Specific capacity reduces 12.8%.
The above results show that compared to the lithium battery based on LNMCO/C, the lithium of the cLNMCOM-2 based on surface modification is electric
The high rate performance in pond and the specific discharge capacity at 1 C, hence it is evident that improve.
Embodiment 5
Other with embodiment 4, the difference is that, 300 μ L 2- ethyl aniline are added to and fill 10 g LNMCO powders（Powder
The size of body particle is 2 ~ 18 μm）50 mL containers in, container is sealed, shake container make LNMCO powders and 2- ethylo benzenes
Amine is uniformly mixed, and is cured 10 days at room temperature.During curing, it being shaken every day container 4 times, each shake time is no less than 10 min,
The LNMCO positive electrode samples of surface modification are obtained after maturation period.
During button cell assembles, electrolyte selects 1 mol L‒1LiBF4It is dissolved in ethylene carbonate：Carbonic acid diformazan
Ester：Diethyl carbonate（Volume ratio is 1:1:1）, remaining is the same as embodiment 4.
Compared to originate lithium batteries of the LNMCO as positive electrode, using the LNMCO of surface modification as the lithium of positive electrode electricity
Pond, the specific discharge capacity at 1 C can be improved 27.3%.
Embodiment 6
Other with embodiment 3, the difference is that, 200 μ L 3,4-rthylene dioxythiophenes are added to and fill 10 g LCO powder
Body（The size of powder granule is 2 ~ 10 μm）50 mL containers in, container is sealed, shake container make LCO powders and 3,4- second
Alkene dioxy thiophene is uniformly mixed, and is cured 14 days at room temperature.During curing, it is shaken every day container 3 times, each shake time is no less than
5 min obtain the LCO positive electrode samples of surface modification after the maturation period.
During button cell assembles, electrolyte selects 1 mol L‒1LiN (SO2CF3)2It is dissolved in ethylene carbonate：Carbon
Dimethyl phthalate：Diethyl carbonate（Volume ratio is 1:1:1）, remaining is the same as embodiment 3.
Compared to originate lithium batteries of the LCO as positive electrode, using the LCO of surface modification as the lithium battery of positive electrode,
Specific discharge capacity at 1 C can be improved 24.8%.
Embodiment 7
Other with embodiment 1, the difference is that, 300 μ L 3- N-ethyl pyrrole Ns are added to and fill 10 g LFP powders（Powder
The size of particle is 0.5 ~ 5 μm）50 mL containers in, container is sealed, shaking container keeps LFP powders and 3- N-ethyl pyrrole Ns mixed
It closes uniformly, cures 7 days at room temperature.During curing, it is shaken every day container 3 times, each shake time is no less than 2 min, maturation period
After surface modification LFP positive electrode samples.
During button cell assembles, electrolyte selects 1 mol L‒1LiN (SO2C2 F5) it is dissolved in ethylene carbonate：
Dimethyl carbonate：Diethyl carbonate（Volume ratio is 1:1:1）, remaining is the same as embodiment 1.
Compared to originate lithium batteries of the LFP as positive electrode, using the LFP of surface modification as the lithium battery of positive electrode,
Specific discharge capacity at 1 C can be improved 26.7%.
Embodiment 8
Other with embodiment 1, the difference is that, 100 μ L 3- vinyl thiophenes are added to and fill 10 g LCO/C powders
（The size of powder granule is 0.1 ~ 2 μm）50 mL containers in, container is sealed, shake container make LCO/C powders and 3- second
Alkenyl thiophene is uniformly mixed, and is cured 14 days at room temperature.During curing, it is shaken every day container 4 times, each shake time is no less than 5
Min obtains the LCO/C positive electrode samples of surface modification after the maturation period.
Compared to originate lithium batteries of the LCO/C as positive electrode, using the LCO/C of surface modification as the lithium of positive electrode electricity
Pond, the specific discharge capacity at 1 C can be improved 17.5%.
Embodiment 9
Other with embodiment 3, the difference is that, 300 μ L 3- ethyl aniline are added to and fill 10 g LMO/C powders（Powder
The size of body particle is 1 ~ 10 μm）50 mL containers in, container is sealed, shake container make LMO/C powders and 3- ethylo benzenes
Amine is uniformly mixed, and is cured 10 days at room temperature.During curing, it being shaken every day container 4 times, each shake time is no less than 10 min,
The LMO/C positive electrode samples of surface modification are obtained after maturation period.
Compared to originate lithium batteries of the LMO/C as positive electrode, using the LMO/C of surface modification as the lithium of positive electrode electricity
Pond, the specific discharge capacity at 1 C can be improved 19.1%.
Claims (10)
1. a kind of lithium battery of the positive electrode based on surface chemical modification, which is characterized in that used surface chemical modification
Positive electrode powder；
Preferably, the lithium battery is button-type lithium cell.
2. the lithium battery of the positive electrode based on surface chemical modification as described in claim 1, which is characterized in that the knob
Button lithium battery recycles the specific discharge capacity of 100 circles at 1 C（Based on positive electrode）Reach 70 ~ 140 mA h g‒1, capacity
Conservation rate is 85 ~ 92%, and capacity is 0.4 ~ 1.8 mW h.
3. the lithium battery of the positive electrode based on surface chemical modification as described in claim 1, which is characterized in that
The button-type lithium cell, it is positive active material to have used the positive electrode powder of surface chemical modification, and lithium piece is negative
Pole, microporous polypropylene membrane are diaphragm.
4. the lithium battery of the positive electrode based on surface chemical modification as claimed in claim 3, which is characterized in that the button
Battery further includes electrolyte, and electrolyte is 1 mol L‒1LiPF6、LiBF4、 LiN(SO2CF3)2Or LiN (SO2C2 F5) molten
In ethylene carbonate：Dimethyl carbonate：Diethyl carbonate（Volume ratio is 1:1:1）Mixed liquor.
5. the lithium battery of the positive electrode according to any one of claims 1-4 based on surface chemical modification, which is characterized in that
The positive electrode powder of the surface chemical modification is that the surface of positive electrode has polymer-modified layer；The anode
Material is LiCoO2、LiCoO2/C、LiMn2O4、LiMn2O4/C、LiFePO4、LiFePO4/C、LiNi x Mn y Co z O2 (x + y +z=1) or LiNi x Mn y Co z O2/C (x + y + z=1), wherein the mass percentage of carbon in carbon coating positive electrode
Less than 5%；
The polymer-modified layer is conducting polymer oligomer；The conducting polymer oligomer, to contain 8 ~ 14 lists
The oligomer of body, weight average molecular weight distribution are 522 ~ 1276；Molecular weight distribution index is 1.1 ~ 1.3；
Preferably, the monomer is aniline, thiophene, pyrroles, 2-aminotoluene, 3- methylanilines, 2- ethyl aniline, 3- ethylo benzenes
Amine, 2- vinyl aniline, 3- vinyl aniline, 3,4- ethene dioxythiophenes, 3 methyl thiophene, 3- ethylthiophenes, 3- vinyl
Thiophene, 3,4- ethylene dioxies pyrroles, 1- benzyl -3,4- ethylene dioxies pyrroles, 3- methylpyrroles, 3- N-ethyl pyrrole Ns or 3- vinyl
Pyrroles.
6. the lithium battery of the positive electrode based on surface chemical modification as claimed in claim 5, which is characterized in that the conduction
Polymer oligomer, monomer are pyrroles, and N 1s high-resolution XPS spectrum figures are shown positioned at the peak of 400,400.7,402 eV；Alternatively,
The conducting polymer oligomer, monomer are thiophene, and S 2p figures are shown positioned at the peak of 163.8 and 164.8 eV；Alternatively,
The conducting polymer oligomer, monomer are aniline, N 1s high-resolution XPS spectrum figures show positioned at 399.2,400.0,
401.0 the peak of eV.
7. the lithium battery of the positive electrode based on surface chemical modification as claimed in claim 5, which is characterized in that polymer is repaiied
The quality of decorations layer accounts for about the 0.05 ~ 3% of surface modification positive electrode quality.
8. the lithium battery of the positive electrode based on surface chemical modification as claimed in claim 5, which is characterized in that the surface
The positive electrode powder of chemical modification is prepared using following method：
A. under room temperature environment air conditions, positive electrode powder is transferred in container；The volume of powder is held no more than container
Long-pending 60%；
B. it by coating material, is added in the container described in step a, container is sealed；Coating material and positive electrode powder
The volume mass ratio of body is 0.5 30 mL/kg；
C. by mixing in coating material and container of the positive electrode powder described in step b, curing obtains surface chemical modification
, the target positive electrode powder that ageing resistance is strong.
9. the lithium battery of the positive electrode based on surface chemical modification as claimed in claim 5, which is characterized in that in step a
The room temperature environment air conditions, range of temperature therein are 0 40 °C, and the relative humidity of surrounding air is 20
80%；
Positive electrode described in step a is LiCoO2、LiCoO2/C、LiMn2O4、LiMn2O4/C、LiFePO4、LiFePO4/C、
LiNi x Mn y Co z O2 (x + y + z=1) or LiNi x Mn y Co z O2/C (x + y + z=1), wherein carbon coating anode material
The mass percentage of carbon is less than 5% in material；
Positive electrode powder described in step a, the mesh of size >=800；
Coating material described in step b is aniline, thiophene, pyrroles, 2-aminotoluene, 3- methylanilines, 2- ethylo benzenes
Amine, 3- ethyl aniline, 2- vinyl aniline, 3- vinyl aniline, 3,4- ethene dioxythiophenes, 3 methyl thiophene, 3- ethyl thiophenes
Pheno, 3- vinyl thiophenes, 3,4- ethylene dioxies pyrroles, 1- benzyl -3,4- ethylene dioxies pyrroles, 3- methylpyrroles, 3- ethyl pyrroles
It coughs up or 3- vinyl pyrroles；
Mixing described in step c, mode are stirring, shake or vibrate；
Curing described in step c, curing time are 7 30 days, stir material during curing daily 24 times, every time when stirring
Between be 1 30 min.
10. a kind of preparation method of such as claim 1-9 any one of them button-type lithium cells, which is characterized in that use
The positive electrode powder of surface chemical modification is positive active material, and lithium piece is cathode, 1 mol L‒1LiPF6、LiBF4、
LiN(SO2CF3)2Or LiN (SO2C2 F5) it is dissolved in ethylene carbonate：Dimethyl carbonate：Diethyl carbonate（Volume ratio is 1:1:1）
For electrolyte, microporous polypropylene membrane is diaphragm, and CR2032 button cells are assembled in the glove box full of dry argon gas；
Its assembling sequence is anode cover-positive plate-electrolyte-diaphragm paper-electrolyte-lithium piece-negative electrode casing；
Sealing pressure is 45-55 kg/cm3。
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| CN101630728A (en) * | 2009-04-16 | 2010-01-20 | 华中科技大学 | High energy density lithium secondary battery electrode and preparation method thereof |
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| CN102569724A (en) * | 2010-12-08 | 2012-07-11 | 比亚迪股份有限公司 | Preparation method for composite material used for anode of lithium ion battery |
| CN103910899A (en) * | 2014-04-11 | 2014-07-09 | 中国科学院化学研究所 | High conductivity polymer coating and preparation method and application thereof |
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2018
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| CN101630728A (en) * | 2009-04-16 | 2010-01-20 | 华中科技大学 | High energy density lithium secondary battery electrode and preparation method thereof |
| CN102569724A (en) * | 2010-12-08 | 2012-07-11 | 比亚迪股份有限公司 | Preparation method for composite material used for anode of lithium ion battery |
| CN102280656A (en) * | 2011-07-04 | 2011-12-14 | 南陵恒昌铜箔制造有限公司 | Preparation method of lithium ion battery with positive electrode covered by conductive polymer |
| CN103910899A (en) * | 2014-04-11 | 2014-07-09 | 中国科学院化学研究所 | High conductivity polymer coating and preparation method and application thereof |
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